At startup, data storage systems are configured by a system installation engineer according to requirements of the system, as well as according to requirements of hosts using the system. Typically, the process of configuration is relatively time-consuming, and depending on the system's size and complexity, may take hours or even days before the system is operating smoothly.
Changes to the configuration of an operating data storage system, while not necessarily taking such lengths of times as those needed at startup, may still require considerable time, depending on the type of configuration change. Furthermore, while the change is being implemented, the storage system is not available to the hosts. The time requirement and the unavailability both cause problems for operation of the storage system.